Three novel polyhydroxylated steroids, (25S)-5a-cholestane-3ß,5a,61ß5,a ,1 6ß,26-hexol 15- sulphate (l),( 25S)-5a-cholestane-3ß,6ß,7a,8,15a,16ß,26-hept(4o)l and (25S)-5a-cholestane-3ß,4ß,6ß,7a,S,- 15a,16ß,26-octol (5), have been isolated from a Pacific deep-water starfish of the genus Rosaster. They cooccurr with two known polyhydroxysteroids (2 and 3). The novel compound 5 showed antifungal activity.

SMIB 1, SMIB 2, SMIB 3, SMIB 4, SMIB 5

Le benthos profond récolté tout d'abord lors des campagnes océanographiques MUSORSTOM IV (1) et CHALCAL (2), puis lors des campagnes de récoltes SMlB (1986, 1987, 1989) s'est avéré être extrèmement riche en invertébrés divers dont beaucoup sont nouveaux. L'abondance et l'originalité de cette faune nous a conduit à étudier une cinquantaine d'organismes recoltés entre 200 et 700m: éponges (40), échinodermes (1 O), alcyonaires (2), madréporaires (1).

CHALCAL 1, MUSORSTOM 4

Six morphotypes of small mussels (Bivalvia: Mytilidae) were found attached to naturally sunken wood collected in the Bohol Sea (Philippines). These specimens are related to the large Bathymodiolus mussels that are found worldwide at cold seeps and hydrothermal vents. In these habitats, the mytilids harbour sulphur- and methane-oxidizing endosymbionts in their gills and depend on the energy and carbon provided by the symbionts. In this study, bacteria associated with the gills of wood-associated mussels are characterized using molecular and microscopic techniques. The existence of bacteria in the lateral zone of gill filaments in all specimens is demonstrated. Comparative analyses of 16S rRNA gene and adenosine 5'-phosphosulphate (APS) reductase gene sequences indicate that the bacteria are closely related to sulphur-oxidizing endosymbionts of Bathymodiolus. FISHs using specific probes confirm that sulphur oxidizers are by far the most abundant, if not the only bacteria present. Electron micrographs displayed mostly extracellular bacteria located between microvilli at the apical surface of host gill epithelial cells all along the lateral zone of each gill filament. In some specimens, occasional occurrence of intracellular bacteria with similar morphology was noted. This study provides the first molecular evidence for the presence of possible thiotrophic symbiosis in sunken wood ecosystems. With their epibiotic bacteria, wood-associated mussels display a less integrated type of interaction than described in their seep, vent and whale fall relatives.

PANGLAO 2005

Two cases of human intoxication causes by the lyophilized powder of Lissoclinum bistratum sluiter. A New Caledonian ascidian are reported. The symptoms observed were caused by a substance designated bistramide A (C40H68N2O8) of hitherto unknown chemical structure. Preliminary toxocological investigations indicate that bistramide A may effect the central nervous system leading to paresthesia ans loss of muscle ton. A progressive decrease in cardiac rythm was also observed in animal. Bistramide A (1,4X10M) did not alter the resting potential of frog heart and skeletal muscle but reduced the amplitude and duration of cardiac action potential ans prolonged the interval between actions potentials, Bistramide A also has a marked cytotoxic effect on cancer cells KB and on normal endothelial cells. Howewer, it has not, been possible to relate the cytotoxic property to the symptoms of intoxication. Bistramidea may originate from the urochordate itself or from symbiotic algae

SMIB 1

Modern two-dimensional NMR techniques have been used here in order to study the structure of a recently isolated cytotoxic drug, bistramide A. Mass spectroscopy indicated a Mr of 704 corresponding to an apparent molecular formula of C40H68N2O8. All structural information was obtained from 1H and 13C NMR. 1H-1H and 1H-13C COSY in combination with relayed 1H-1H-13C COSY and 1H-13C COLOC were used for obtaining all crucial connectivies required for determing the partial structure of this natural product.

SMIB 1

Aztequynol A (1), isolated from the nepheliospongid sponge, Petrosia sp., from the Banc Azteque off New Caledonia, represents the first case of a structurally defined C-branched polyacetylene based on high-energy collisionally-activated decomposition tandem mass spectrometry of lithium adducts which may have wide application in natural product structural analysis.

SMIB 1, SMIB 2, SMIB 3, SMIB 4, SMIB 5, SMIB 6, SMIB 8, SMIB 9

In comparison with other ecosystems, biodiversity and natural-product diversity of the New Caledonian marine ecosystem, comprising lagoons, barrier reefs, and deep waters in seamount regions, are described here phylogenetically with the aid of molecular drawings and tabulation of data. Admittedly, since the inception of these studies in 1977, the comparison is biased by selection of New Caledonian organisms on the basis of positive pharmacologically oriented bioassays. However, we show that these and other distortions must be accepted to draw any comparison on a regional basis, which, nonetheless, turn out to be useful for the progress of knowledge, particularly in directing future explorations of biodiversity in the search for new pharmacologically active metabolites.

AZTEQUE, SMIB 1, SMIB 10, SMIB 2, SMIB 3, SMIB 4, SMIB 5, SMIB 6, SMIB 8, SMIB 9

La caractérisation du substrat des fonds marins est une première étape fondamentale pour la prédiction des habitats benthiques, la gestion des ressources biologiques ou encore l’inventaire des ressources minérales. Ce travail est d’autant plus essentiel lorsque l’on traite la Zone Economique Exclusive (ZEE) de Nouvelle-Calédonie considérée, à l’échelle globale, comme une des régions les plus riches en termes de biodiversité marine. Ce stage, qui a pour but de cartographier la nature des fonds de la ZEE, s’inscrit dans le cadre du projet de mise en place d’une politique de « gestion intégrée de l’Espace maritime de la Nouvelle-Calédonie ». La méthodologie employée pour répondre à cet objectif a consisté à traiter l’ensemble des données d’imagerie acoustique acquises pour la plupart au cours des campagnes ZoNéCo et à les corréler aux prélèvements disponibles. Ce travail a permis de réaliser la carte de réflectivité des fonds marins couvrant 34 % de la ZEE et la mise à jour de la base de données des prélèvements comptabilisant aujourd’hui plus de 880 échantillons. L'examen approfondi de ces nouvelles données a permis de créer une classification adaptée à la Nouvelle-Calédonie s'inspirant des normes européennes EUNIS. Au final, deux cartes ont été produites : (i) une carte présentant la dureté des fonds marins de la ZEE et (ii) une carte présentant la nature et le type de substrat de la ZEE. Ces nouveaux résultats révèlent la présence de grands ensembles sédimentaires et la découverte de nouvelles structures géologiques. Sur un plan appliqué, ce travail a amélioré la connaissance des ressources minérales de la ZEE et a permis de créer les couches d’informations utiles aux futurs travaux de prédiction des habitats benthiques marins. Il a enfin été l’occasion de dresser des préconisations visant à réduire les incertitudes et orienter les travaux futurs.

BATHUS 1, BATHUS 2, BATHUS 3, BATHUS 4, BIOCAL, BIOGEOCAL, CALSUB, CHALCAL 1, GEMINI, MUSORSTOM 5, MUSORSTOM 6, NORFOLK 1, SMIB 1, SMIB 10, SMIB 2, SMIB 3, SMIB 4, SMIB 5, SMIB 6, SMIB 9, VOLSMAR

SMIB 1, SMIB 2, SMIB 3, SMIB 4, SMIB 5, SMIB 6

The sesquiterpene isocyanide stylotelline isolated from the marine sponge Stylotella sp. was asigned the structure 1a (absolute stereochemietry) on the basis of spectral - essentially 2D-NMR - and chemical data.

SMIB 1, SMIB 2, SMIB 3